Apple rolled out iOS 11 earlier this week. The redesigned software includes big changes and minor tweaks, and the update is available on smartphones as far back as the iPhone 5S. Or you can wait and buy an iPhone 8 or iPhone 8 Plus, or hold off for the iPhone X coming later this year.

One new feature gives users the ability to place emergency phone calls from a locked iPhone. Previously, you could only call 911 from a locked screen, or by telling Siri to "charge my phone 100 percent."

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However, dialing 911 from a locked screen doesn't always work, especially if your screen is damaged.

Now, pressing the sleep/wake button five times will call emergency services. It will also alert the emergency contact programmed into your phone and relay your location.

Other new iOS 11 features include the Accessibility Setting, which lets you type questions for Siri.

There's the updated Notes app that does handwriting detection and scans documents, and new special effects in Messages. There are new photo effects to loop Live Photos or make long exposures, and Do Not Disturb will try and keep drivers focused on the road.

Apple's peer-to-peer payment tool, which lets people send cash to friends over Messenger or using Siri, will come to iOS 11 in a fall release.